Junction #67 Park Road Access to Seminole Canyon Texas State Park, Campground & Historical Site. Jagged canyons have cut through the Chihuahuan Desert wilderness out where the Pecos River flows into the Rio Grande. People of antiquity once lived in these natural rock shelters carved into the canyon walls by the river. They painted distinctive ancient symbols on the walls that tell us of their passing.Walk the rugged landscape; climb down into the canyons to see the renowned pictographs. Camping: Facilities include the park interpretive center, with exhibits relating to the history of the canyon area, campsites with water and electricity; picnic sites, restroom with showers.